Emperor Akihito is expected to step down on or around his 85th birthday on Dec 23 next year, and public broadcaster NHK said the abdication rites, last performed 200 years ago, will likely be modernised.

The date of his abdication may be announced as early as next summer by a government decree, after consultations with the Imperial Household Agency. "This is an issue that affects the country's foundations, its history and its future," said Prime Minister Shinzo Abe yesterday after the passage of the one-time law.

Emperor Akihito will assume the title "joko" (Grand Emperor), while Empress Michiko will get the new title "jokogo". Tokyo will also decide the name of a new era, with the Heisei (achieving peace) era coming to an end.

The Emperor's Birthday national holiday will be changed from Dec 23 to Feb 23, the Crown Prince's birthday.

Walter Sim